Wear-testing machines



Feb. 18, 1969 s. E. TAUB WEAR-TESTING MACHINES Sheet iled April 26, 1967FIG.I

1 III Ir) III! INVENTOR STEPHEN E.TAUB BY ATTORNEYS Feb. 18, 1969 s. E.TAUB 3,427,859

WEAR-TESTING MACHINES Filed April 26, 1967 Sheet 2 of :1

INVENTOR STEPHEN E. TAUB Fgb. 1a, 1969 r'ilsd April 26, 1967 S. E. TAUBWEAR-TESTING MACHINES INVENTOR ATTORNEY United States Patent 3,427,859WEAR-TESTING MACHINES Stephen E. Taub, Brooklyn, N.Y., assignor toInstitutional Research Council, Inc., New York, N.Y., a corporation ofNew York Filed Apr. 26, 1967, Ser. No. 633,852 U.S. Cl. 73-7 Int. Cl.G01u 3/56, 19/02 4 Claims ABSTRACT OF THE DISCLOSURE The inventioncomprises a wear tester for floor coverings which simulates wear inducedby normal walking. A wear member strikes the covering first on its heel,and then the heel is raised as the toe strikes the covering. This motionalso induces rotary movement to the covering support. Twisting action isprovided to the wear member while it is in contact with the covering tosimulate wear induced as a person turns a corner.

Prior art Various wear-testing machines are known, but they have notbeen successful. The pressure on the carpeting and the shape of weartool are not variable on most of the known testing machines. The type ofwear induced by the known testing machines does not resemble the wearinduced by a person walking on the carpet and the results obtained bythe testing machines do not correspond to the results obtained underactual use conditions.

Objects of the invention The apparatus of the invention for wear-testingfloor covering comprises a rotatable table provided with means forsecuring a test specimen thereon, at least one shoe means mounted overthe portion of the said table where the test specimen lies, means forraising and lowering said shoe means whereby first the heel portion ofthe shoe means contacts the test specimen under pressure and then thesole portion of the shoe means contacts the test specimen and means forvarying the pressure of the shoe means on the test specimen, the saidtable being rotated by the movement of the shoe means.

The rotatable table may be round and provided about its bottomcircumference with wheels or bearings riding on the support means forthe table. This arrangement allows the table to remain level when underpressure from the shoe means and to remain rotatable. In a preferredembodiment, the table is provided with means to vary the amount offriction between the table and the wheels so that the amount of forcenecessary to rotate the table can be varied. This has the advantage thatthe amount of wear on the test specimen can be varied since as theamount of drag increases, the more energy is required by the shoe meansto rotate the table which increases the friction and, therefore, wearbetween the shoe means and the test specimen.

While the round table may be made of any hard material, it is preferablymade of hard metal and is provided with a top layer of regular woodflooring in order to provide a base as similar as possible to the typeof base a carpeting is usually used with. For floor coverings which areto be used on a hard surface such as a concrete or stone floor, the woodlayer may be omitted to provide a similar hard base for the testspecimen.

The test specimen with or without an under layer is preferably the samesize and shape as the rotatable table and is tightly held thereon. Oneconvenient means for holding the test specimen in place is two metalrings which are bolted or screwed to the table, one ring being about thecircumference of the table and the second ring about the center of theround table.

The shoe means which are used to induce wear on the test specimen and torotate the table are mounted above that portion of the table on whichthe test specimen lies and preferably there are two shoe means onopposite sides of the table so that a greater degree of wear can beinduced in a given period of time. The shoe means may be in the shape ofa normal mans shoe or a womans high heel shoe in order to determinedifferent types of wear to which the test specimen will be subjected. Ina preferred embodiment, the shoe means may be laterally adjustable sothat a wide area of wear may be induced on the test specimen.

At least one of the shoe means is adapted so that as the shoe is loweredto the test specimen on the table first the heel of the shoe comes incontact with the test specimen and the sole of the shoe means comes incontact With the test specimen while the heel is lifted off the testspecimen. This arrangement not only simulates the wear induced by normalwalking, but it also provides a force which turns the table so that thenext lowering of the shoe means will come in contact with anotherportion of the test specimen. This result can be simply achieved byproviding the shoe means with a bar or cylinder across the middle orforward portion of the heel of the shoe means so that the bar orcylinder acts as a fulcrum for the shoe means.

In a preferred embodiment of the invention, the weartester apparatus isprovided with means for twisting the sole of the shoe means while it isin contact with the test specimen which movement simulates the wearinduced by a person turning a corner. One simple means for providingthis twisting action is to provide the shoe means with a metal plate onthe toe of the shoe means which is synchronized to engage a push rod ina pneumatic cylinder when the sole is in contact with the test specimen,the said push rod pushing the toe plate laterally to provide thetwisting movement. The degree of twist can be easily varied by changingthe length and/or speed of stroke of the push rod and/ or changing thelateral position of the shoe means.

The raising and lowering of the shoe means may be effected by attachingthe shoe means to rods connected to overhead cylinders which may beoperated hydraulically or pneumatically to force the shoe means upon thetest specimen under pressure and then to raise the shoe means for thenext cycle. The amount of pressure applied by the said cylinders ispreferably varied over a wide range, i.e., 1 to 5,000 pounds per squareinch, to induce different degrees of wear on the test .specimen. Thesaid cylinders are preferably laterally adjustable so that the shoemeans may be moved laterally.

In a preferred embodiment of the Wear-testing apparatus, the speed ofthe raising and lowering of the shoe means should be variable so thatthe apparatus can simulate a varying gait, ranging from a slow walk to afast walk or running.

If desired, the apparatus may be provided with an automatic counter todetermine the number of times the shoe means comes in contact with thetest specimen and may be further provided with an automatic shut offmeans so that the apparatus will shut itself off after a predeterminednumber of steps.

The advantage of the apparatus of the invention resides in the fact thatthe fiber damage, soiling and wear of the resilient carpeting induced bythe apparatus is the same as that produced under actual use conditionssince the movement of the shoe means is the same as that of a personwalking. The test results obtained in a matter of two or three days withthe apparatus of the invention would require several years of wear underactual use conditions. Moreover, the wear results are reproducible sothat different types of floor coverings can be accurately compared fortheir durability. The degree of wear of the resilient floor covering canbe determined by visual observation, the loss in weight of the coveringand/ or the weight of detritus collected. The floor coverings can berated for different characteristics such as frictional resistancebetween underlay and carpeting, compression set and carpet life.

Referring now to the drawings:

FIG. 1 is a cross-sectional view of one embodiment of the wear-testingmachine of the invention.

FIG. 2 is a partial plan view of the same embodiment along line 22 ofFIG. 1, and FIG. 3 is a plan view of the same embodiment along line 33of FIG. 1.

FIG. 4 is a plan view along the line 44 of FIG. 2, showing the means forlaterally moving the shoes.

FIG. 5 is a cross-sectional view of the shoe means as the heel firstcomes in contact with the test floor covering and FIG. 6 is across-sectional view of the shoe means as the sole comes in contact withthe test floor covering just before the shoe means is twisted.

Referring to the drawings in detail, the entire apparatus is supportedby frame 1. Round table 2 is supported on a plurality of wheels orrollers 3 which are arranged about the bottom circumference of the table2 so that the table 2 will rotate due to the movement of the shoe means.Additional wheels 4 are positioned horizontally about the outercircumference of table 2 to keep the table in a fixed lateral position.The table 2 is comprised of a metal base 5 and a wood base 6 thereoverwhich simulates a normal wood floor. To simulate a concrete or stonefloor, the wood base 6 is removed. The test specimen 7 of resilientfloor covering, with or without an underlay, is laid on the table 2 andis held securely in position thereon by inner metal ring 8 and outermetal ring 9 which are bolted to the table with bolts 10. This preventslumps or wrinkles forming in the test specimen during the testoperation.

Shoes 11 and 12 are mounted directly above the portion of test specimen7 which is to be subjected to the wear tests and are preferably onopposite sides of the table 2. The said shoes are connected by rods 13and 14 to cylinders 15 and 16 which are preferably operatedpneumatically and which are synchronized so that both shoes are raisedand lowered together. The compressed air or hydraulic fluid is fed underpressure to cylinders 15 and 16 from a supply source (not shown) bytubes 17 and 17a and 18 and 18a to force shoes 11 and 12 upon the testspecimen under pressure, hold them in position and then raise them forthe next cycle. The pressure can vary from about 1 to 5,000 p.s.i. Thespeed of raising and lowering the shoe means is adjusted by varying theoperation of the cylinders.

Cylinders 15 and 16 are preferably laterally adjustable and are somounted on frame 1, whereby a broadened area of wear is obtained whichgives more accurate results since floor coverings are not alwayscompletely uniform. FIGS. 2 and 4 illustrate one means of moving theshoes laterally after each raising and lowering of the shoe. Eachcylinder is attached by a metal rod 19 to a disc 20, said rods beingattached offset from the center of disc 20, whereby turning of disc 20will bring together or move apart cylinders 15 and 16. Disc 20 isattached by shaft 21 to notched gear 22 which is turned by the back andforth motion of rod 23 attached to piston 24. As gear 22 is rotated, onenotch for each raising and lowering of the shoes, the disc 20correspondingly rotates in increments whereby the cylinders are movedlaterally in increments towards or away from each other. By adjustingthe radial placement of rods 19 on disc 20, the lateral movement of theshoes by notched gear 22 may be varied.

FIGS. 5 and 6 illustrate the movement of the shoes as they come incontact with the test specimen 7 and a preferred connection with rods 13and 14. Shoe 11 is provided with a solid block 25 inside thereof whichis securely attached to rod 13 and the shoe is provided with a lateralmetal cylinder 26 in the middle of the heel 27. A sleeve 31 is providedon the block 25 having an upwardly opening slot 32 which is adapted toreceive the piston rod 13. An enlarged cylindrical portion 33 is securedon the free end of the piston rod 13 and is received within the sleeve.The cylinder includes a downwardly projecting rod 34 which fits within anotch 35 provided in the block 25. In the position illustrated in FIGURE5 the heel of the shoe 11 is swung to a position lower than the toeportion and it is this position that first contacts the test specimen.As rod 13 comes down, the back of heel 27 and cylinder 26 contact thefloor covering first and as rod 13 continues to descend, the cylinder 26acts as a pivot with the back of the heel rising off the floor as thesole of the shoe and front portion of the heel come in contact with thefloor covering. This movement causes the table 2 to rotate on rollers 3.By varying the amount of drag on the table, the degree of wear can bevaried.

In order to simulate Wear which occurs where a person turns a corner,shoe 11 is preferably provided with a metal plate 28 securely attachedto the toe thereof. A pneumatic cylinder 29 with a push rod 30 ismounted so that push rod 30 can push on the plate 28 when the shoe 11 isin the position shown in FIG. 6, which twists the shoe to one side whileunder pressure. The amount of twist can be varied by changing the lengthand/or speed of stroke of push rod 30 and/or by changing the lateralposition of the shoe. It should be apparent that to insure that the heelof the shoe first contacts the specimen a biasing member of some sortshould be provided to maintain the position of the shoe in FIGURE 5 inthe free state. In the preferred embodiment a spring 36 is secured atthe upper portion of plate 28 and suitably secured at the other end tothe frame. As the piston rod 13 retracts the shoe from its specimencontacting position, the spring 36 returns the shoe to the positionillustrated in FIG- URE 5.

The apparatus is preferably equipped with an automatic counter and anautomatic shut off switch so that the number of steps by the shoes maybe counted and the apparatus can be shut off after a predeterminednumber of steps. While mens shoes have been illustrated in the figures,womens shoes or simulations of shoes of any style can also be used.

Various modifications of the apparatus of the invention may be madewithout departing from the spirit or scope thereof and it is to beunderstood that the invention is to be limited only as defined in theappended claims.

I claim:

1. Apparatus for inducing wear in floor coverings comprising a rotatabletable having a test specimen provided thereon, shoe means spaced fromsaid specimen, means for mounting said shoe means for rotationalmovement about a first axis parallel to the plane of said table, meansfor biasing said shoe to a first position whereby the heel is nearestsaid specimen, means for moving said shoe means whereby the lattercontacts said specimen, fulcrum means mounted on said heel whereby saidshoe is rocked about said heel when the latter contacts said specimen torotate said table.

2. Apparatus according to claim 1 wherein said fulcrum member is acylinder having an axis parallel to said first axls.

3. Apparatus according to claim 1 including means for biasing said toeportion about an axis at right angles to said table whereby twisting isimparted to said specimen.

4. Apparatus according to claim 1 including means for moving said shoemeans laterally of said table whereby an equal distribution of shoecontact is distributed over said specimen.

References Cited UNITED STATES PATENTS 1,906,175 4/1933 Millet 73-72,895,326 7/1959 Fesperman et a1 73-7 5 3,134,255 5/1964 Oliver et a1.73-7 3,323,349 6/1967 Savage et a1. 73-7 LOUIS R. PRINCE, PrimaryExaminer.

10 J. NOLTON, Assistant Examiner.

